Signatures of an intermediate 2d Coulomb phase at low temperatures

The study of the ground state of spinless fermions in 2d disordered cluster s (Phys. Rev. Lett., 83 (1999) 1826) has suggested the existence of a new q uantum phase for intermediate Coulomb energy to kinetic energy ratios rs. E xact diagonalization of the same small clusters shows that its low-energy e xcitations (quantum ergodicity above a few "hexatic" excitations characteri zed by oriented currents) significantly differ from those occurring in the Fermi glass (weak r(s)) and in the pinned Wigner crystal (large r(s)). The "hexatic" excitations vanish for temperatures of order of the Fermi tempera ture.